Development of anti-static coatings

As early as 1948, the United States announced the silver and made of conductive epoxy adhesive patent, this is the first open conductive coating. 1950s, Japan began production in silver and carbon-based anti-static coating system. 1960s United States, Britain, Japan and other countries have developed anti-static coating. 1980s, the world anti-static coating technology and heating technology, a rapid development, China is also in the 1950s began to study and application of anti-static coating.Typically, polymers are mostly electrical insulation materials, the surface resistivity and volume resistivity Áv Ás great(Ás of 1014 ~ 1017© · m, Áv for the 1015 ~ 1018© · m). Volume resistivity is less than 100© · m for the conductive polymer materials for conductivity and electromagnetic shielding; volume resistivity of 100 ~ 106© · m for the semiconductor material, mainly used for heat resistance of parts and electrodes; electrical resistivity of 105 ~ 1010© · m of the material mainly used for antistatic materials. When the material volume resistivity is less than 108© · m, or surface resistivity is less than 109© · m, even when the electrostatic charge will soon discharge to the surrounding environment. As a function of coating anti-static coating, manganese powder the surface resistivity is usually 105 ~ 109© · m, can take advantage of electrostatic discharge effect of the accumulation of electrostatic charge in the surface discharge in time to avoid the accumulation of static electricity caused by a variety of problem, it is widely used in electronics, electrical appliances, aviation, chemical, printing and other industries.Add-and anti-static coating is divided into two types of intrinsic type, intrinsic antistatic coating technology is not yet mature, there is currently a large number of anti-static coating is generally used to add paint. Add antistatic coating is non-conductive base resin material to add some antistatic conductive filler to achieve the function, only the conductive filler volume fraction up to a certain extent in order to form a conductive network or pathway, reflecting the nature of electrical conductivity. Commonly used conductive fillers are: carbon based materials (carbon black, graphite, etc.), metal powder (silver, copper, nickel powder), metal oxide semiconductor (tin oxide, iron oxide, zinc oxide), conductive nano-particles and anti- static additives. Which metal powder density, boron powder the formation of conductive paths require larger volume fraction, surface oxidation, may reduce or even lose their conductivity and corrosion resistance is poor, thus affecting other performance coating, so the metal powder as a conductive filler application subject to certain restrictions; antistatic agent temperature resistance, water resistance, oil resistance, corrosion resistance, durability is poor, anti-static performance is unstable; early antistatic coatings commonly used as a conductive filler of carbon based materials, graphite and carbon black conductive dispersion is poor, products, color black, is not easy to modulation of other lighter color; with the development of technology, the gradual emergence of semiconductor and nano-conductive metal oxide powder new conductive filler, and antistatic coating was applied, this material is light in color , easy-to-color, anti-static coating of rich color system, but such materials, when used alone to add a large amount of dispersion stability is poor, and paints and coatings will affect the performance of carbon-based materials is generally used in conjunction with the . In recent years there has been used as a conductive filler of the conductive fiber antistatic coatings, conductive fiber diameter as small, large aspect ratio, only a small amount of conductive fibers can be formed in the conductive network of the coating can reduce the coating other properties. Source:http://www.mhcmp.com